PHNOM PENH, Cambodia -- Park rangers in Cambodia are being trained to survey wild bears to help protect them from being hunted for their bile which is used in traditional Chinese medicines, a conservationist said Thursday.

Wild bears, known as Asiatic black bears and Sun bears, continue to be hunted in Cambodia to meet a growing demand in China and Vietnam, said Matt Hunt, the Southeast Asia Program Manager for the Australian-based Free the Bears Fund.

The bitter, green bile extracted from the gallbladders of endangered bear species, has long been used by Chinese traditional medicine practitioners to treat eye, liver and other ailments.

In a statement, Hunt's group described the practice as "cruel and unnecessary."

The course for 24 Cambodian park rangers will teach them to identify the bears' feces, claw marks on trees and termite mounts that the animals have broken in to. The information gathered will give conservationists a greater understanding of the animals and determine their population status, which is threatened by hunting and trafficking, Hunt said.

Hunt said it was not known how many wild bears remain in the Cambodian wild as few studies have been done.

The World Conservation Union says Asiatic black bears and Sun bears are considered "threatened to endangered."

Hunt's group said in a statement that more than 10,000 bears in China and 4,000 in Vietnam are kept in inhumane conditions at bear farms.

The rangers are being trained by two international experts -- Gabriella Fredriksson, who has spent years tracking and rehabilitating bears in the forests of East Kalimantan, Borneo, and Robert Steinmetz from the World Wildlife Fund in Thailand, Hunt said. Eight observers from Thailand, Malaysia and Indonesia were also attending.

Hunt's group has sponsored a sanctuary at Phnom Tamao Zoo, about 28 miles south of the capital Phnom Penh, where 78 rescued bears live.

He said the group has rescued three cubs, aged nine and 14 weeks old, from traffickers this month.